JP2019152545A - Foreign material detector - Google Patents

Abstract

To provide a foreign material detector which can appropriately detect a small foreign material mixed in a lubricant in a gear device.SOLUTION: A foreign material detector (1) is for detecting a foreign material in a lubricant sealed in a gear device. The detector includes a first detection unit (11) and a second detection unit (12) separate from each other. The first detection unit (11) has a magnetic power and connects with the second detection unit (12) by a deposited foreign material (F) so that a signal showing detection of the foreign material (F) is output.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a foreign matter detection device that detects foreign matter in a lubricant enclosed in a gear device.

  Generally, a gear device such as a reduction gear is worn internally by rotational movement, and foreign matters such as metal powder are mixed in the lubricant. And wear advances to a limit amount and reaches a lifetime. When wear progresses to near the end of its life, a relatively large piece of metal may peel off inside.

  Patent Document 1 discloses a sensor that detects a metal piece mixed in a lubricant by arranging a pair of detection pieces facing each other in a lubricant of a gear device. According to this sensor, when a metal piece having a predetermined size or more is sandwiched between the pair of detection pieces, the pair of detection pieces can be conducted to detect the metal piece mixed in the lubricant.

JP 2017-207416 A

  However, the sensor disclosed in Patent Document 1 has a problem that only a large foreign object can be detected because the foreign object is detected by being sandwiched between a pair of detection pieces. For example, if the distance between the pair of detection pieces is reduced in order to detect a small foreign object, the lubricant between the detection pieces does not flow, and the detection ability is significantly reduced. For this reason, even if the operating time of the gear device is increased and the amount of small foreign matter in the lubricant increases, there is a problem that the sensor of Patent Document 1 cannot detect this.

  An object of this invention is to provide the foreign material detection apparatus which can detect appropriately the small foreign material mixed in the lubricant of a gear apparatus.

The present invention
A foreign matter detection device for detecting foreign matter in a lubricant enclosed in a gear device,
Comprising a first detector and a second detector arranged at an interval,
The first detection unit has a magnetic force,
The first detection unit and the second detection unit are connected to each other through the accumulated foreign matter so that a signal indicating the detection of the foreign matter is output.

  According to the present invention, it is possible to appropriately detect small foreign matters mixed in the lubricant of the gear device.

It is a block diagram which shows the foreign material detection apparatus which concerns on embodiment of this invention. It is explanatory drawing showing the detection state of the foreign material. It is a block diagram which shows the modification of a foreign material detection apparatus. It is sectional drawing of the gear apparatus which shows the arrangement | positioning location of the sensor part of a foreign material detection apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram illustrating a foreign object detection device according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing a foreign object detection state.

  The foreign object detection device 1 of the present embodiment supplies an operating voltage to the sensor unit 10 that detects a foreign object, the output unit 15 that outputs a detection signal when a foreign object is detected, and the sensor unit 10 and the output unit 15. And a power source 17.

  The sensor unit 10 includes a first detection unit 11 and a second detection unit 12 having conductivity, which are arranged at intervals. The 1st detection part 11 and the 2nd detection part 12 are magnetized magnetic bodies, and have the capability (ability to generate a magnetic force or a magnetic field) to attract magnetic materials, such as iron powder which is a small foreign material. The 1st detection part 11 and the 2nd detection part 12 have a plate-shaped form, for example, and are arrange | positioned so that a plate surface may mutually oppose. The opposing surfaces are preferably different magnetic pole surfaces. The sensor part 10 is arrange | positioned in the location where the lubricant of a gear apparatus flows. Then, a voltage is applied from the power source 17 to the first detection unit 11 and the second detection unit 12 so that a weak current flows through the two conductive lines when they are conducted.

  An interval L1 (see FIG. 2) between the first detection unit 11 and the second detection unit 12 is set to an interval that is larger than the diameter of a small foreign object that is a detection target and can sufficiently flow the lubricant. Further, the interval L1 is set depending on how much foreign matter in the lubricant has increased. In the present embodiment, the small foreign object to be detected means metal powder generated by normal wear of the gear device or a small metal piece that does not significantly affect normal operation of the gear device. Further, the interval L1 between the first detection unit 11 and the second detection unit 12 is appropriately set according to the “small foreign matter accumulation amount” to be detected.

  The output unit 15 detects a weak current flowing through a conductive wire connected to the first detection unit 11 and the second detection unit 12, and when a current equal to or greater than a threshold flows, a detection signal indicating detection of a foreign object is output from the gear device. Output to the outside.

<Detection operation>
In the gear device, wear occurs in each part due to rotational movement, and small foreign matters F such as metal powder are mixed in the lubricant. Due to the flow of the lubricant, some foreign matter F enters between the first detection unit 11 and the second detection unit 12 in the sensor unit 10. Then, the small foreign matter F is attracted to the first detection unit 11 and the second detection unit 12 by magnetic force, and accumulates on the first detection unit 11 and the second detection unit 12.

  When the operating time of the gear device increases and internal wear progresses, the foreign matter F accumulated in the first detection unit 11 and the second detection unit 12 increases, and if this exceeds a predetermined amount, the foreign matter F accumulates via the accumulated foreign matter F. The 1 detection part 11 and the 2nd detection part 12 are connected. Then, the first detection unit 11 and the second detection unit 12 become conductive, and current flows between them, so that the output unit 15 outputs a detection signal. The detection signal is output to an external control device, for example, and used for warning control such as turning on a lamp indicating deterioration of the gear device.

  In general, the gear device reaches the end of its life as wear progresses. According to the foreign object detection device 1 described above, when the wear of the gear device has progressed to a predetermined degree, this can be detected to warn of the deterioration of the gear device. As a result, the gear device can be replaced or maintained at an appropriate stage before the gear device fails.

<Modification>
FIG. 3 is a configuration diagram illustrating a modified example of the foreign object detection device.

  The foreign object detection device 1A according to the modified example is different from the sensor unit 10 in FIG. 1 in the configuration of the sensor unit 10A. The sensor unit 10 </ b> A includes a first detection unit 11 </ b> A, a second detection unit 12 </ b> A, and a magnet 13. 11 A of 1st detection parts and 12 A of 2nd detection parts are metal plates which have electroconductivity, and are arrange | positioned so that a plate surface may mutually oppose. The magnet 13 is a permanent magnet, for example, and is fixed (arranged) on the opposite side of the first detection unit 11A from the second detection unit 12A. The magnet 13 magnetizes the first detection unit 11A and generates a magnetic force that attracts foreign substances of the magnetic material to the first detection unit 11A. Alternatively, the first detection unit 11A may not be a magnetic body, and in that case, the magnet 13 causes a magnetic foreign substance to be placed on the surface of the first detection unit 11A that faces the second detection unit 12A by its own magnetic force. attract. Even if these configurations are employed, the same operation as the detection operation of the foreign object detection apparatus 1 of FIG. 1 described above can be obtained.

<Example of sensor placement>
FIG. 4 is a cross-sectional view of the gear device showing the location of the sensor unit of the foreign object detection device.

  Then, the example which has arrange | positioned the sensor part 10 of the foreign material detection apparatus 1 of embodiment to the eccentric rocking | fluctuation type deceleration device 20 as a gear apparatus is demonstrated.

  First, the speed reducer 20 will be described. The speed reduction device 20 includes an input shaft 21, an output shaft 22, a speed reduction portion 23, and housings (casings) 24 and 25 that cover the periphery of these. Oil seals o1 and o2 are provided between the housing 24 and the input shaft 21, and between the housing 25 and the output shaft 22, respectively.

  The speed reducer 23 swings by the rotation of the eccentric body shaft 31 connected to the input shaft 21, the plurality of eccentric bodies 31a, 31b, 31c provided on the eccentric body shaft 31, and the eccentric bodies 31a, 31b, 31c. A plurality of external gears 32A, 32B, 32C are provided. The external gears 32 </ b> A, 32 </ b> B, and 32 </ b> C have a plurality of inner pin holes that are spaced apart from each other in the circumferential direction at positions offset from the center, and a central through hole through which the eccentric body shaft 31 passes.

  The speed reducer 23 further includes an internal gear 25g provided on the inner peripheral portion of the housing 25, an internal pin 22c passed through the internal pin holes of the external gears 32A, 32B, and 32C, and an anti-load of the internal pin 22c. And a carrier body 34 that holds one end of the side. The internal gear 25g has a plurality of external pins p1 serving as internal teeth and an internal gear main body having a plurality of pin grooves for holding the plurality of external pins p1, and internally connects the external gears 32A, 32B, and 32C. Mesh. The inner pin 22c is provided so as to bulge from the output shaft 22 into a pin shape.

  The speed reduction unit 23 further includes eccentric body bearings 36a and 36b, eccentric body bearings 37a, 37b, and 37c, and main bearings 38a and 38b. The eccentric body shaft bearings 36a and 36b are respectively disposed between the eccentric body shaft 31 and the output shaft 22 and between the eccentric body shaft 31 and the carrier body 34 so as to be relatively rotatable with each other. The eccentric body bearings 37a, 37b, and 37c are arranged between the eccentric bodies 31a, 31b, and 31c and the external gears 32A, 32B, and 32C, respectively, so that they can rotate relative to each other. The housing 25 rotatably supports the carrier body 34 and the output shaft 22 via the main bearings 38a and 38b.

  When the torque is input from the input shaft 21 and the eccentric body shaft 31 rotates, the speed reducing section 23 rotates the eccentric bodies 31a, 31b, and 31c inside the central through holes of the external gears 32A, 32B, and 32C. As a result, the external gears 32A, 32B, and 32C swing at different phases. In the external gears 32A, 32B, 32C, the external teeth farthest from the axis of the eccentric body shaft 31 mesh with the internal gear 25g by swinging, and this meshing position changes in the circumferential direction along with the swing. Specifically, each time the eccentric body shaft 31 makes one rotation, the meshing position of the internal gear 25g and the external gears 32A, 32B, 32C makes one round in the circumferential direction. There is a difference in the number of teeth between the external gears 32A, 32B, and 32C and the internal gear 25g, and the external gears 32A, 32B, and 32C have the above-mentioned difference in the number of teeth each time the meshing position with the internal gear 25g goes around. Rotate. This rotation is transmitted to the output shaft 22 via the inner pin 22c. Thereby, the rotational motion of the input shaft 21 can be decelerated and taken out from the output shaft 22.

  In such a configuration, a relatively large surface pressure is applied to the external teeth of the external gears 32A, 32B, and 32C to cause wear. Foreign matter such as metal powder generated by abrasion flows in the lubricant encapsulated inside the housings 24 and 25. A part of the lubricant flows in a path passing through the space R1 surrounded by the input shaft 21, the carrier body 34, and the housing 24, and a large amount of foreign matter contained in the lubricant is vertically below the space R1. Stays at a rate.

  The sensor unit 10 is disposed at a location facing the space R1 of the housing 24 where the lubricant flows. Furthermore, the sensor unit 10 may be disposed at a position located vertically below when the speed reducer 20 is used. Such an arrangement location increases the amount of foreign matter that accumulates on the sensor unit 10 in accordance with the progress of the amount of wear of the speed reduction unit 23. Therefore, there is an advantage that it can be detected relatively accurately that the wear of the speed reduction portion 23 has progressed to a predetermined degree. Further, it is not preferable that a large amount of foreign matter stays between the internal gear 25g and the external gears 32A, 32B, and 32C. According to the arrangement of the sensor unit 10, the external gears 32A, 32B, and 32C are separated. There is an advantage that foreign matter can be deposited at the spot.

  As described above, according to the foreign object detection device 1 of the present embodiment, the first detection unit 11 and the second detection unit 12 are arranged at an interval, and the first detection unit 11 has a magnetic force. With such a configuration, the foreign matter is deposited on the first detection unit 11 by the magnetic force while sufficiently flowing the lubricant mixed with the small foreign matter between the first detection unit 11 and the second detection unit 12. be able to. And the signal which shows the detection of a foreign material is output because the 1st detection part 11 and the 2nd detection part 12 are connected by the accumulated foreign material. Thereby, it is possible to detect a state in which wear of the gear device has progressed.

  Further, according to the foreign object detection device 1 of the present embodiment, the second detection unit 12 also has a magnetic force. For this reason, the magnetic force of the 1st detection part 11 and the magnetic force of the 2nd detection part 12 are united, and the capability to deposit a foreign material between these can be improved. Therefore, for example, even when the lubricant flow speed is high or the vibration is high, high foreign substance detection capability can be obtained.

  Further, according to the foreign object detection device 1A of the modified example of the present embodiment, the magnet 13 is used to generate a magnetic force for depositing foreign substances on the first detection unit 11A. Accordingly, it is easier to generate a strong and stable magnetic force at a low cost in the first detection unit 11A than to magnetize the first detection unit 11A having conductivity in advance. Therefore, a high foreign substance detection capability can be obtained stably at low cost.

  The embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment. For example, in the above-described embodiment, an example of the electrical connection form of the sensor unit, the output unit, and the power source is shown. However, this is only a conceptual example, and various general connection forms may be applied. . Moreover, although the 2nd detection part 12 of the sensor part 10 showed the structure which has a magnetic force in the said embodiment, only the 1st detection part 11 may have a magnetic force. Moreover, although the example of arrangement | positioning of the sensor part 10 was shown in the said embodiment, the sensor part 10 may be arrange | positioned in any location, if it is a location where a lubricant flows. Further, as an example of a gear device equipped with a foreign object detection device, an eccentric oscillating speed reduction device has been shown. However, the gear device includes a simple planetary gear device, a flexure meshing gear device, various orthogonal shaft gear devices, various types of gear devices. A parallel shaft gear device or the like may be applied. Also in the eccentric oscillating speed reducer, the above embodiment has shown a so-called center crank type eccentric oscillating speed reducing apparatus in which one eccentric body shaft is arranged at the center of the speed reducer. However, as the eccentric oscillating speed reducer, a so-called distributed eccentric oscillating speed reducer in which two or more eccentric body shafts are offset from the axis of the speed reducer may be applied. In addition, the details shown in the embodiments can be changed as appropriate without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1, 1A Foreign object detection apparatus 10, 10A Sensor part 11, 11A 1st detection part 12, 12A 2nd detection part 13 Magnet 15 Output part F Foreign object 20 Deceleration device 21 Input shaft 22 Output shaft 23 Deceleration part 24, 25 Housing o1, o2 Oil seal R1 space

Claims (3)

A foreign matter detection device for detecting foreign matter in a lubricant enclosed in a gear device,
Comprising a first detector and a second detector arranged at an interval,
The first detection unit has a magnetic force,
A signal indicating the detection of a foreign object is output by connecting the first detection unit and the second detection unit via a deposited foreign object,
Foreign object detection device. The second detector also has magnetic force,
The foreign object detection device according to claim 1. The first detection unit includes a metal plate and a magnet, and the magnet is disposed on the opposite side of the metal plate from the second detection unit.
The foreign object detection device according to claim 1 or 2.

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